The thick black curve is the numerically-integrated solution to the mass action equations (49a)–(49d), and the unfilled circles mark the inner solution given by (103). The leftmost dashed vertical line corresponds to tc2, and the rightmost dashed vertical line corresponds to . The lower dotted horizontal line corresponds to y = ℓ; The constants (without units) used in the numerical simulation are: , , , k1 = 1, k2 = 1, k3 = 1, k−3 = 1, k4 = 100 and k−1 = 1. Time has been mapped to the t∞ scale: t∞(t) = 1 – 1/ln[t + exp(1)], and c2 has been numerically-scaled by its maximum value.